Sorry, I wasn't very clear, I understand all that, my query was why
libelf is required in the first place, thus breaking what was
previously a working build.
So, I looked, and it was introduced in January as a dependency for the
new gresource tool.
Thus, my recommendation would actually be to just disable this tool on
32-bit SunOS or at least build that tool only with large file
disabled, rather than break large file support completely for every
single package which uses glib2, because my guess is the former is
much more palatable for users.

Wouldn't these users already be limited wrt to file size due to other
programs linking to the system libelf?